The ability to control the dissolution of a downhole well component in a variety of solutions is important to the utilization of non-drillable completion tools, such as sleeves, frac balls, hydraulic actuating tooling, and the like. Reactive materials for this application, which dissolve or corrode when exposed to acid, salt, and/or other wellbore conditions, have been proposed for some time. Generally, these components consist of materials that are engineered to dissolve or corrode.
While the prior art well drill components have enjoyed modest success in reducing well completion costs, their consistency and ability to specifically control dissolution rates in specific solutions, as well as other drawbacks such as limited strength and poor reliability, have impacted their widespread adoption. Ideally, these components would be manufactured by a process that is low cost, scalable, and produces a controlled corrosion rate having similar or increased strength as compared to traditional engineering alloys such as aluminum, magnesium, and iron. Ideally, traditional heat treatments, deformation processing, and machining techniques could be used on the components without impacting the dissolution rate and reliability of such components.
Prior art articles regarding calcium use in magnesium are set for in Koltygin et al., “Effect of calcium on the process of production and structure of magnesium melted by flux-free method” Magnesium and Its Alloys (2013): 540-544; Koltygin et al., “Development of a magnesium alloy with good casting characteristics on the basis of Mg—Al—Ca—Mn system, having Mg—Al2Ca structure.” Journal of Magnesium and Alloys 1 (2013): 224-229; Li et al., “Development of non-flammable high strength AZ91+Ca alloys via liquid forging and extrusion.” Materials and Design (2016): 37-43; Cheng et al. “Effect of Ca and Y additions on oxidation behavior of AZ91 alloy at elevated temperatures.” Transactions of Nonferrous Metals Society of China (2009): 299-304; and Qudong et al., “Effects of Ca addition on the microstructure and mechanical properties of AZ91 magnesium alloy.” Journal of Materials Science (2001): 3035-3040.